Thread: JD w/Kohler motor starter system questions

I have a 2001 model JD riding mower with a Kohler 15 HP motor. It has a problem with the starter, and I would like some help diagnosing it. Here is the issue:

When I start the mower, sometimes the starter keeps on running even after the mower starts. It disengages the flywheel, but continues to spin even after I stop the ignition. It will keep on spinning until the battery runs down, and that is the only way to get it to stop. Usually if the mower runs for any length of time (ten minutes or so) the starter will stop spinning.

I only noticed this problem when I forgot to choke the motor once before turning the ignition key, so the mower cranked but didn't start - and then when I turned the key off the engine stopped turning over (starter disengaged) but the starter kept spinning. Turning the key off did not stop it from spinning, and turning it back to start did NOT reengage the starter... like I said it keeps going until the battery dies.

My initial feeling is that the problem is something electrical. I know the battery is pretty weak, so I thought I would start with replacing that, but should I also replace the solenoid? What about the starter, could it be bad? Are there any quick tests I can do on it while I have it all apart?

Hit the solenoid to see if it is hanging up. with starter motor turning on its own like you described, remove any small wires from the solenoid except the battery wires to see if it may be your ignition switch hanging up.

sounds like a bad solenoid to me, they're pretty cheap, I'd replace it first. Also look at the backside of your ignition switch for corrosion. Corrosion may bridge two contacts and make a complete circuit that won't disengage. Possible but not likely. I, personally, would start with replacing the solenoid.

I put it all back together and tried pulling the small wires from the solenoid while it was spinning with the key off like I described. It kept on running until the battery died like before.

Then, I replaced the battery. That seems to make a big difference. It spins a while with the key off now, but does stop after five seconds or so. Then if I turn the key to start again it will try starting again as normal. When it does start, it works the same way. Starter runs on for about five seconds or so after it disengages the flywheel, but finally stops.

I can certainly live with the way it works now, it's just not something I'm used to. I will probably replace the solenoid next if this runs down my new battery, but it looks like it's going to work OK now since the starter is actually stopping now after a few seconds.

I would be scared that it would re engage the flywheel and start knocking off teeth.... If its' still doing it I would still try to fix the problem rather than just wait for it to break something else....